Three local deer killed by hunters during the fall rifle season tested positive for the disease, which slowly destroys the animals' brains and always ends in death. There is no evidence that the illness can spread to humans.

"We knew at some point CWD would probably come here," state Game Commission regional information and education supervisor Barry Leonard said Friday. "We want to narrow down how prevalent it is at this point."

While the disease was found in an Adams County farm deer in October, this week's discovery marks its first identification in the state's wild deer population.

As a result, Blair and Bedford counties are set to come under special Game Commission rules as wildlife officials work to find the outbreak's precise sources, Leonard said. Under those rules, hunters permitted to kill crop-destroying deer on so-called "red tag" farms are ordered to turn in the animals' heads for testing, while officers also plan to test any deer struck and killed by cars.

"We want to know the areas the deer were frequenting," he said.

Officials will trace the infected deer's tags to the hunters who killed them. The hunters will then lead Game Commission officers to the spots where the animals were shot, Leonard said.

By tightening the search and testing more deer nearby, officials hope to stop the spread of chronic wasting disease.

Left unchecked, the illness can ravage wild deer, elk and moose populations, causing bizarre behavior and unstoppable weight loss until the animals die. It is believed to spread through prions, or infectious proteins, possibly through animals' bodily fluids.

"It's decimated the herd" in Wyoming, said Bill Carter of Altoona, who has traveled repeatedly to Wyoming for hunting trips.

Before the disease struck in Wyoming, Carter said, he could identify 25 bucks in a day. Last year it took four days to spot a single buck, he said.

Determining the illness' range can be difficult - only dead deer can be tested, and in many cases chronic wasting disease can lie dormant for a year or more, Game Commission Regional Director Brad Myers said Friday.

It's not yet clear how the disease reached Blair and Bedford counties. While infected deer have been found in recent years in upstate Maryland, Myers noted that it's a long jump from the state line to the Altoona area.

A deer from an infected Adams County farm was brought to East Freedom and eventually a Huntingdon farm before escaping into the woods last year. But that deer was shot and tested negative for the disease, the state Department of Agriculture announced in December.

Myers said a deer with chronic wasting disease "either walked across the border or it came across in a truck," Myers said. States with confirmed infections are often subject to strict deer-carcass export rules.

The recently identified infected deer were processed by local butchers, who sometimes preserve the animals' heads for official inspection, Leonard said. He declined to identify the butchers involved.

Game Commission officials are set to schedule a Monday press conference in Harrisburg, Myers said.

A local public information meeting is also in the works, likely to be held in mid-to late March somewhere in southern Blair County, he said.